Textile-sizing processes



United States Patent 3,515,581 TEXTILE-SIZING PROCESSES Robert A. Isaksen, East Longmeadow, Raymond I. Longley, Jr., Springfield, and Charles R. Williams, Longmeadow, Mass., assignors to Monsanto Company, St. Louis, Mo., a corporation of Delaware No Drawing. Continuation-impart of applications Ser. No. 481,932 and Ser. No. 481,975, both filed Aug. 23, 1965. This application June 25, 1968, Ser. No. 739,608

Int. Cl. C08f 29/30; D06m 15/36 US. Cl. 117--139.5 9 Claims ABSTRACT OF THE DISCLOSURE Disclosed herein is an improvement in a process for sizing textiles wherein the improvement comprises employing as the textile sizing agent a system comprising a water-soluble polyvinyl alcohol, a compound having a molecular weight of between 60 and 2000 and containing hydroxyl groups, amide groups, ether groups or mixtures thereof, and a compound selected from the group consisting of magnesium, calcium, barium, cupric, zinc, strontium and manganese chlorides, bromides, iodides, nitrates, nitrites, thiocyanates, acetates, formates, propionates and butyrates; magnesium, cupric, zinc, strontium and manganese sulfates; barium hydroxide and mixtures thereof.

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation-in-part of co-pending application Ser. No. 481,932, filed Aug. 23, 1965 and co-pending application Ser. No. 481,975, also filed Aug. 23, 1965, both now abandoned.

BACKGROUND OF THE INVENTION Field of the invention The present invention relates generally to an improvement in a process for sizing textile materials.

Description of the prior art The use of polyvinyl alcohol as a textile sizing agent is well-known. It is particularly useful for this purpose because of its toughness and high tensile strength. The very toughness that makes it desirable for this application, however, has limited its use because of the difliculties inherent in applying so tough a material to the textile material.

Among the problems that have arisen with the use of polyvinyl alcohol as a textile sizing agent are:

(1) Skin formation-The resin is usually applied to the yarn from aqueous solution contained in open, heated vats. Evaporation of solvent from the vat causes a tough skin of polymer to form on the surface and this skin then draws up on the yarn as the yarn passes through the vat.

(2) Visc0sity.As molecular weight of the resin increases, its physical properties, e.g. toughness, improve. However, the viscosity of the sizing solution increases correspondingly. Thus, it has been found that about the highest solids concentration that can be employed in the sizing solution is 7-8%.

(3) Separation on split r0ds.-In practice, a large number of individual yarn filaments are sized simultaneously by arranging them parallel to each other in the shape of a broad fiat ribbon. This ribbon of individual strands is then dipped into sizing vats, after which it is led over heated drums for drying. After drying, the sizing process requires that the strands be again separated by means of split rods. It has been found with polyvinyl 3,515,581 Patented June 2, 1970 "Ice alcohol, however, that its dry toughness is so great that the yarn strand will rupture before the sizing film.

(4) Ec0n mz'cs.The cost of polyvinyl alcohol is high and any means of extending it without decreasing its necessary desirable properties is advantageous.

There exists, then, a need in the textile industry for a sizing system based upon polyvinyl alcohol which will exhibit high toughness when wet, but reduced toughness when dry, will have little or no tendency toward skin formation and which can be provided to the industry at substantially reduced cost.

It is, therefore, an object of this invention to provide an improved method for sizing textiles wherein the improvement lies in employing a system which, with or without further additives, provides superior compositions for use in exacting service where, to be desirable, a material must combine numerous specific properties.

It is a further object of this invention to provide lower cost compositions which satisfy complex use requirements in service heretofore requiring the specification of more expensive materials.

SUMMARY OF THE INVENTION Each of the above objects has been realized through the use as the textile-sizing agent of a system comprising a high molecular weight water soluble polyvinyl alcohol,

a low molecular weight water soluble compound containing hydroxyl groups, amide groups, or ether groups or combinations thereof, and a compound selected from the group consisting of magnesium, calcium, cupric, zinc, strontium and manganese chlorides, bromides and iodides, nitrates, nitrites, thiocyanates, acetates, formates, propionates and butyrates; magnesium, cupric, zinc, strontium and manganese sulfates; barium hydroxide and mixtures thereof.

More particularly this invention relates to an improvement in a process for sizing textile materials wherein the improvement comprises employing as the textile sizing agent a system comprising in combination:

(A) A polyvinyl ester at least 60% hydrolyzed whereby it is soluble in water,

(B) A compound soluble to the extent of at least onehalf percent by weight in water, said compound having a molecular weight of 60-2000 and containing substituents selected from the class consisting of:

(1) hydroxyl groups,

(2) amide groups,

(3) ether groups and (4) mixtures thereof, and

(C) At least one compound selected from the group consisting of:

(1) magnesium, calcium, barium, cupric, zinc, strontium t and manganese chlorides, :bromides and iodides;

(2) magnesium, calcium, barium, cupric, zinc, strontium and manganese nitrates, nitrites, thiocyanates, acetates, formates, propionates and butyrates;

(3) magnesium, cupric, zinc, strontium and manganese sulfates; and

(4) barium hydroxide.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The polyvinyl alcohol polymers which are to be used in the practice of this invention are water-soluble polymeric materials having a molecular weight above 2000 and containing a plurality of recurring hydroxyl groups. Typically, these polyvinyl alcohols are prepared by the partial or complete hydrolysis of vinyl esters such as polyvinyl formate, polyvinyl acetate, polyvinyl propionate,

polyvinyl butyrate, polyvinyl stearate, polyvinyl trifluoroacetate, etc. For water-solubility, it is necessary that the polyvinyl alcohol be at least 60% hydrolyzed, and preferably at least 80% hydrolyzed.

The second component employed in the preparation of the systems to be used in the process of this invention is a particular class of compounds which impart several desirable properties to the polyvinyl alcohol. For example, the use of these compounds allows the extension of the polyvinyl alcohol permitting lower cost, reduces its surface tack, and provides control over the moisture sensitivity properties of the polymer which permits significant performance improvements as textile sizes.

The low molecular weight compounds which may be used in the practice of this invention include those materials which are soluble to the extent of at least one-half percent by weight in water, have a molecular weight of between 60 and 2000 and contain either hydroxyl groups, amide groups, ether groups or mixtures thereof. Typical low molecular weight compounds which are employed in this regard are sucrose, ethylene glycol, disaccharides, dextrin, corn syrup, starch hydrolyzates, urea, thiourea, ethylene glycol, glycerine, benzyl alcohol, diethylene glycol, polyethylene oxides and polypropylene oxides. Generally, the preferred low molecular weight compounds used in the practice of this invention are starch hydrolyzates and disaccharides.

The individual components making up the textile sizing agent may be combined in any practical manner to form what is believed to be a complex compound. For example, the low molecular weight compound and the salt may be first combined and this combination may then be used to form the complex with the high molecular weight, water-soluble polyvinyl alcohol. Alternatively, all the components may be brought together simultaneously to form the complex compound.

Generally, the components of the polymeric complexes to be used in this invention will be combined by dissolving them together in water, however, the complexes may be produced by various techniques such as extrusion, calendering or film casting. In general, the adaptability of the particular polymeric complex to fabrication by any given technique will depend upon factors which can be readily controlled by the choice of the particular watersoluble polyvinyl alcohol used as a starting material and/ or by the choice of the low molecular weight compound and the particular metallic salt. Where the components have been combined by means such as extrusion or calendering, it will, of course, then be necessary to dissolve the complex in an aqueous medium for application to the textile material. Note that, as used herein, the term textile material is intended to include the fibers from which the textile is constructed and thus the sizes of this invention can, and preferably will, be applied to fibers, as well as to finished textiles.

The choice of the particular metallic salt to be used as the complexing agent, and the amount to be used with a given amount of a particular polyvinyl alcohol and a low molecular weight compound will be governed to some extent by the operating conditions during fabrication and the spectrum of properties desired in the final product. For example, greater amounts of metallic salt increase the flexibility of the sizes under some moisture conditions.

It can thus be seen that the particular combination of primary ingredients making up commercially useful compositions within the range of this invention will depend upon both the most feasible method of preparation and the specific combination of end use requirements, and will be varied from one application to another to achieve the optimum overall cost-performance ratio. Within the above-mentioned constraints, compositions comprising 30 to 90 parts by Weight of the polyvinyl alcohol, to 70 parts by weight of the low molecular weight material, and 1 to 50 parts by weight of the particular metallic salts of this invention produce polymeric complexes having good physical properties. For an optimum balance of physical properties, 50 to 70 parts by weight of the polyvinyl alcohol, 15 to 30 parts by weight of the low molecular weight material and 5 to 15 parts by weight of the metallic salt are employed. 7

The polyvinyl alcohol, the low molecular weight component and the metallic salts may be prepared by any of the methods conventionally used in the art.

The following examples are presented to illustrate the invention and are not to be construed as limitations thereof. Unless otherwise indicated, all quantities mentioned are on a part by weight basis.

EXAMPLE I Fifty parts of polyvinyl alcohol hydrolyzed) are slurried in 900 parts of water. The polyvinyl alcohol is dissolved by heating the slurry at C. for 15 minutes, after which 35 parts of sucrose and 15 parts of MgCl -6H O are added.

This solution is designated as textile solution 1. A second solution, designated textile sizing solution 2, is prepared by dissolving sufficient polyvinyl alcohol in water to provide a 10% solids solution. A third solution, desig nated textile sizing solution 3, is prepared by dissolving 60 parts of polyvinyl alcohol and 40 parts of sucrose in water to provide a 10% solids solution. To each solution is added 0.5 weight percent of a waxy lubricant.

Textile yarn (warp 5900 ends of 65/35 polyester/cotton yarn 30/1) is sized separately with each of the sizing solutions prepared above and is run on a commercial 9 can slasher having an internal steam pressure of 35 pounds per square inch. The size box temperature is maintained at 180 F. and the squeeze roll is held at a total pressure of 1200 pounds. Each of the separately sized warps is observed for slasher performance and tested for weaving performance.

The yarn sized with textile sizing solution 1, having an applied total solids of 10% weight percent based on the weight of the yarn, is cleanly and easily separated at the split rods with little or no shedding. The yarn has an applied total solids of about 10 weight percent based on the weight of the yarn. The sizing solution in the size box remains clear and homogeneous throughout the operation and exhibits no tendency to form a surface skin. The sized yarn is subsequently woven on commercial looms. The looms operate at a weaving efliciency of 92% with 0.5 warp stops per hour. (Warp stops result when a breakage of the sized yarn occurs.)

In sizing the same grade of warp yarn with textile sizing solution 2, the solution forms a surface which must be continually removed to allow operation of the slasher.

The yarn, sized under the same conditions but with the second sizing solution and having the same amount of total applied solids as in the previous case, is difficult to separate at the split rods and causes severe yarn breakage. It is impossible to obtain yarn which is useable on the looms due to excess breakage of the yarn on the slasher.

The above described sequence of operations is repeated using textile solution 2 again, except that only 7% total solids are applied to the textile yarn. Although breakage of warp yarns occurs, the breaks are suflicientl reduced to provide enough yarn for the weaving operation. Measurement of the weaving efliciency is impossible due to continual breakage of the warp yarn on the looms during the weaving operation.

The above described sequence of operations is repeated using textile sizing solution 3. The sizing solution exhibits the same tendency to form a skin or fihn as that described in connection with sizing solution 2. Although some end breakage occurs at the split rod section, it is possible to obtain sufficient yarn to weave on the looms. The weaving operation is completed at a weaving efiiciency of 85% with warp stops of about 2.2 per hour. This weaving efiiciency and warp stoppage rate is totally unsatisfactory for a commercial operation in the textile industry.

EXAMPLE II Example I is repeated except that in the textile sizing solution 1 described therein, 15 parts of anhydrous magnesium sulfate is substituted for the 15 parts of The yarn sized with this textile sizing solution, having an applied total solids of 11 /2 weight percent based on the weight of the yarn, is cleanly and easily separated at the split rods with little or no shedding. The sizing solution in the size box remains clear and homogeneous throughout the operation and exhibits no tendency to form a surface skin. The sized yarn is subsequently Woven on commercial looms. The looms operate at a weaving efiiciency of about 94% with approximately 0.4 warp stops per hour.

EXAMPLE III Fifty parts of polyvinyl alcohol (80% hydrolyzed) are slurried in 90 parts of water. The polyvinyl alcohol is dissolved by heating the slurry at 85 C. for 15 minutes, after which 35 parts of sucrose and 15 parts of are added. Films of the resultant material are prepared by casting films of the solution on a glass plate coated with a release agent. The films are dried at elevated temperatures to remove the water. The clear, homogeneous films formed are removed from the substrate and tested for elongation after conditioning the films at various levels of relative humidity. The test results on the film, designated Film A are shown below.

As a control, a polyvinyl alcohol solution is prepared in the manner set forth above but without the addition of sucrose or MgCl -6H O. Films are again cast on a glass plate coated with a release agent and dried at elevated temperatures. The films, designated below as Film B, are also conditioned at identical relative humidities and tested for elongation. The comparative results are set forth in Table I.

EXAMPLE IV Example III is repeated except that 15 parts of magnesium sulfate (MgSO-7H O) is substituted for the 15 parts of MgCl-6H O employed therein. Again, the elongation at corresponding relative humidities is much improved over the control (Film B) of Example III. See Table II.

TABLE II Relative humidity (percent): Elongation (percent) 0 Examples I and II demonstrate that the textile sizing systems of this invention exhibit superior properties as compared to warp sizes of the prior art. In particular, the number of warp stops has been shown to be significantly reduced. The decrease in warp stops is directly related to the increased ability of the systems of this invention to elongate under tension, as demonstrated by Examples III and IV. v

This relationship is explainable by considering that a warp stop is caused by a break in the yarn, the occurrence of a break in the yarn is a function of a break in the sizing film and fewer sizing film breaks under tension will occur in a film having improved ability to elongate. With this in view, it has been found that the performance of a particular sizing system can be predicted in the laboratory by methods such as those employed in Examples III and IV, thereby making possible a great saving in time, expense and inconvenience as compared with actual plant trials. The following examples thus take advantage of this demonstrated relationship.

EXAMPLE V Example III is repeated except that 60 parts of polyvinyl alcohol (99% hydrolyzed) are dissolved in water, and 20 parts of MgCl-6H O and 30 parts of ethylene glycol are added. As a control, a polyvinyl alcohol solution is prepared as above, but only ethylene glycol is added to the solution. The resultant film, designated Film B, is cloudy, lacks homogeneity and exudes the ethylene glycol. The results obtained after conditioning the films in the manner set forth in Example III are as follows:

TABLE III Elongation (percent) Relative humidity (percent) Film A Film B EXAMPLE VI Example V is repeated using parts of polyvinyl alcohol (60% hydrolyzed), 10 parts of urea, and 10 parts of cupric chloride (CuCl -2H O). Solution preparation and film casting are carried out at room temperature. A clear, flexible continuous film is obtained.

EXAMPLE VII Example V is repeated using 80 parts of olyvinyl alcohol (60% hydrolyzed), 13 parts of urea, and 7 parts of cu-pric acetate Cu(C H O -H O. Solution preparation and film casting are carried out at room temperature. Again, a clear, flexible continuous film is obtained. L

Additional films are prepared by combining the salts, polyvinyl alcohol and low molecular weight compounds in the proportions indicated in Table IV, and preparing 50 315 the films in the same manner and under the same condi- 80 610 tions as those set forth in Example III.

TABLE IV Parts by Parts by Parts by Example Hydroxy-containing polymer weight Salt weight Low M.W. compound weight VIII Polyvinyl alcohol (60% hydro1yzed) Barium hydroxide Ba(OH)2.8H 0 5 Sucrose 10 IX Polyvinyl alcohol (80% hydrolyzed) Barilun formats Ba(CHO2)2 5 Corn syrup 40 X do 43 Cupric acetate Cl1(C2H3O2)2.I-I2O 7 Urea 3O 20 Zinc acetate Zn(C H3O2)g.2I-IO 20 Thiourea.-. 60 40 Strontium nitrate S!(NO3)2.4HQO 30 Glycerine 30 25 Manganese nitrate MI1(NOa)z.6H2O 40 Benzyl alcohol 35 25 Magnesium sulfate MgSO4.7H2O 50 Polyethylene oxide 25 In preparing aqueous solutions for use in sizing textile yarns, it is necessary that the vinyl ester homopolymers be at least 60% hydrolyzed. The exact degree of hydrolysis necessary in the vinyl ester to produce water-solubility will vary with the amount and solubility characteristics of the particular vinyl ester constituent present. The aqueous sizing solution is applied to the textile yarn in amounts of 1-20 weight percent based upon the weight of the textile yarn. Textile yarns sized with the polymeric compositions used in this invention exhibit excellent slasher performance and weaving efficiency with a minimum of warp stops, permitting eificient removal of the sized yarn from the slasher without yarn breakage.

The compositions described for use in this invention have a relatively broad range of use temperatures and combine exceptional resistance to chemical attack, low flammability and resistance to the deleterious eflfects of prolonged exposure to heat and light.

Hardness, rigidity, dimensional stability, creep resistance, toughness, tensile strength, elongation and tear strength may readily be adjusted over the range associated with thermoplastic materials of this nature by varying the proportions of the polymeric constituents and liquid plasticizers, if any.

Other additives may be used for optimizing the processing performance and/or end use properties of the compositions such as stabilizers, co-stabilizers, anti-oxidants, lubricants, coated and/or uncoated fillers, pigments and light screeners.

While in the foregoing specification, specific composi- 1 tions and steps have been set out in considerable detail for the purpose of illustrating the invention, it will be understand that such details of composition and procedure may be varied widely by those skilled in the art without departing from the spirit of this invention.

What is claimed is:

1. In a process for sizing textile materials the improvement which comprises employing as the textile sizing agent a system comprising in combination:

(A) from 30 to 90 parts by weight of a polyvinyl ester at least 60% hydrolyzed whereby it is soluble in water,

(B) from to 70 parts by weight of a compound soluble to the extent of at least one-half percent by Weight in water, said compound having a molecular weight of 60-2000 and containing substituents selected from the class consisting of:

(1) hydroxyl groups,

(2) amide groups,

(3) ether groups and (4) mixtures thereof, and

(C) from 1 to 50 parts by weight of at least one compound selected from the group consisting of:

(1) magnesium, calcium, barium, cupric, zinc, strontium and manganese chlorides, bromides and iodides;

(2) magnesium, calcium, barium, cupric, zinc strontium and manganese nitrates, nitrites, thiocyanates, acetates, formates, propionates and butyrates;

(3) magnesium, cupric, zinc, strontium and manganese sulfates; and

(4) barium hydroxide.

2. The improved process of claim 1 wherein the hydrolyzed vinyl ester is present in amounts of 50-70 parts by weight, the compound having a molecular weight of -2000 is present in amounts of 15-30 parts by weight and the compound of part C is present in amounts of 5-15 parts by weight.

3. The improved process of claim 1 wherein the compound having a molecular weight of 60 to 2000 is a disaccharide.

4. The improved process of claim 1 wherein the compound having a molecular weight of 60-2000 is a Starch hydrolyzate.

5. The improved process of claim 1 wherein the compound having a molecular weight of 60-2000 is ethylene glycol.

6. The improved process of claim 1 wherein the compound having a molecular weight of 60-2000 is urea.

7. The improved process of claim 1 wherein the compound having a molecular weight of 60-2000 is glycerine.

8. The improved process of claim 1 wherein the compound of part C is magnesium chloride.

9. The improved process of claim 1 wherein the compound of part C is magnesium sulfate.

References Cited UNITED STATES PATENTS 1,914,989 6/1933 Bosland et a1. 106-139 2,395,616 2/1946 Dangelmajer 260-174 2,565,962 8/1951 Goldstein et al 260-8 2,743,194 4/1956 Berner et al 117-1395 3,144,351 8/1964 Anderson 117-1395 X WILLIAM D. MARTIN, Primary Examiner T. G. DAVIS, Assistant Examiner U.S. Cl. X.R. 

